This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This research project is concerned with the functional organization and information processing of the second visual area (V2). Area V2 neurons are known to process elemental aspects of the visual scene such as stimulus orientation, color and depth, and are thought to participate in the combination of visual information that is processed independently by other neurons. Histology has revealed repeated cycles of 'thin', 'pale'and 'thick'stripe compartments across Area V2, and there is a reported tendency for different neural response characteristics in each stripe class (e.g., color-preferring in thin stripe, cf. orientation-preferring in pale and thick stripes). In this project we will investigate the functional role of marginal zones of the thin and pale stripes in the processing of color and orientation. Intrinsic optical imaging methods will map the collective response preference of neurons at sub-millimeter scale, and functionally define the thin/pale marginal zones. Based on this map, single neurons will be selected for comprehensive electrophysiological characterization. By combining functional mapping methods with single neuron electrophysiology we aim to identify unique neuronal properties and mechanisms (such as combinatorial coding and selectivity maintenance) associated with these neural locales in Area V2. These experiments, in particular, are intended to improve understanding of the basic mechanisms associated with cortical visual processing. However, in general, they also seek to reveal fundamental relationships between single neuron response and the collective response of the surrounding neural environment. Understanding this relationship is important because many brain measurement techniques can only record neural responses at the collective rather than single neuron scale. Knowledge of this relationship will aid understanding of the neural basis of imaged brain function, and guide future brain data interpretation.